Gas Drainage Sealing Method Based on Radial Strong Expansion

Abstract

The sealing method of gas drainage based on radial strong expansion includes the following steps: (1), determine the sealing position and sealing depth; (2), determine that it has good compactness, high strength, high expansibility and strong permeability Sealing material with four characteristics; (3), install the radial strong expansion drainage sealing device; (4), insert the radial strong expansion drainage sealing device into the borehole to expand and seal the hole; (5), After the expansion of the polyurethane mixed liquid bag is completed, the orifice pipe is connected to the gas drainage pipe for gas drainage. The device adopted by the invention has the advantages of simple structure, fast sealing speed and easy operation, which can make workers skilled quickly. The invention greatly improves the effective sealing length of the drainage borehole, and due to the compactness of the sealing material, it can fully bear the pressure difference between the drilling and the external roadway, preventing the air in the roadway from passing through the sealing material itself. Cracks enter the borehole.

Description

Technical field [0001] The invention relates to the technical field of coal seam gas drainage, in particular to a method for gas drainage and sealing based on radial strong expansion. Background technique [0002] Mine gas is one of the main factors that seriously threaten coal mine safety production. Gas explosion and gas outburst are the most disasters in coal mines today, causing many casualties and huge property losses every year. Therefore, preventing gas disasters is of great significance for reducing coal mine accidents and ensuring the healthy and sustainable development of the coal industry. [0003] Gas drainage is an important measure to reduce mine gas emission, prevent gas explosion accidents, and prevent coal and gas outburst disasters. In addition, gas is a high-quality environmentally friendly energy source. The extracted gas can be used as fuel for civil use and power generation, and it is also an important chemical raw material. Therefore, gas drainage is of gr...

AI Technical Summary

Problems solved by technology

[0005] The above-mentioned traditional hole sealing method also has the following defects: First, there is no systematic analysis and prediction of the development of coal and rock mass cracks in the two sides of the roadway and the borehole wall, scientifically determine the length of the hole sealing and the depth of the hole sealing, but based on experience or correlation Provisions to determine the sealing length and sealing depth

Due to the limitation of the sealing process, two extremes are prone to occur: either the sealing material is placed at the hole opening, and the sealing depth is shallow, which blocks the softer orifice part of the coal body, and the effective sealing length cannot be guaranteed, resulting in a shallow sealing depth , The pre-extraction gas concentration is low; or, the sealing depth and sealing length are too large, resulting in waste of sealing materials, increased sealing costs, and slow sealing speed

Secondly, there is no suitable standard to judge the adaptability of the properties of the sealing material itself. Most sealing materials are affected by factors such as gas pressure in the broken zone around the drilling, water lock effect, grouting pressure and the properties of the material itself. Penetrating into the cracks in the borehole wall, there are still various micro-cracks and holes in the coal and rock mass around the borehole, and the air in the roadway will still leak through the crack circle around the borehole and infiltrate into the drainage pipeline

Finally, in the traditional sealing technology, the sealing material expands freely in the drilled hole, without being constrained by the axial direction of the drilled hole, and without radial pressure, it is difficult to ensure the compactness of the sealing material itself, resulting in lax sealing.

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